This invention relates generally to fuses for interrupting the flow of current through an electrical circuit upon predetermined overload conditions and, more particularly, to fuses with direct current and alternating current arc interrupting capability.
As is well known, fuses are used in electrical circuits to interrupt the flow of current when there is a short-circuit and/or a full voltage overload current event. Fuses typically include one or more fuse elements electrically connected to two end conductors located at opposing ends of the fuse. In the event of a short circuit and/or a full voltage overload, the temperature of the fuse element increases until a portion of the element melts and breaks. The break in the fuse element typically causes an electric arc to be established.
Sand is typically used to fill the fuse cartridge to surround the fuse elements to assist in quenching an arc. U.S. Pat. No. 4,656,453 describes cartridge fuses that include end plugs that are used for arc quenching. The fuse element passes through the end plugs adjacent to the end conductors. U.S. Pat. No. 5,280,261 describes a current limiting fuse that includes a short circuit strip that has a plurality of 90 degree angle bends along the length of the strip. The multiple bends in the fuse strip cause the strip to contact or come in close proximity of the inside wall of the fuse body. When a short-circuit arc occurs the fuse strip material burns towards the fuse wall creating an interaction with the fuse wall and an increase in pressure, which extinguishes the arc. However, even with the above noted examples of arc quenching, these fuses may not interrupt the circuit satisfactorily.
It would be desirable to provide a fuse that includes arc quenching capabilities during a short-circuit and/or a full voltage overload current interrupt event. It would also be desirable to provide a fuse that reduces arc energy during a short-circuit and/or a full voltage overload current interrupt event.